Dorney Triathlon

Sorry, bookings for this event have been paused due to a certain virus. Visit our blog post for more details.

Organiser's Description

A Sprint or Standard distance triathlon around Dorney Lake. Take the opportunity to race around this unique and inspiring Olympic venue, ideal for a chip timed personal best! The purpose built lake is perfect for the swim, and the flat grounds lend themselves to a totally flat bike and run course.

Each discipline will be accurately marked out with distance flags, and we will have plenty of helpers to keep you on track and to encourage you all the way to the finish.

Start Time



  • Standard Triathlon 1500m swim, 40 km bike, 10 km run
    £58 CLOSED
  • Sprint Triathlon 750m swim, 20 km bike, 5 km run
    £48 CLOSED

Fast & Flat Course

Chip timed results

Unique themed medal

Free official event photos

Fruit & Flapjacks


Inspiring Venue

Dorney Lake, Off Court Lane, Windsor, Berkshire SL4 6QP

Dorney Lake is a 2,200 metre rowing lake owned by Eton College. It is used for many international regattas, and famously hosted the rowing events during the London 2012 Olympics.

Dorney Lake is ideally placed, being within easy reach of London, Heathrow Airport, the M4 corridor and the M3, M25 and M40 motorways.

It is well served by the rail network, with main stations being Slough, Maidenhead and Windsor. Taplow and Burnham train stations are also nearby.

There will be free parking for all participants next to the event village and start and finish!

Starting and finishing outside Dorney Lake boathouse, all three disciplines are within the grounds of Dorney Lake. The swim follows a 750m loop, the cycling course runs along the left side of the lake, the run is alongside the right side of the lake.

Swim Course: You will be guided to the side of the lake at the swim start, straight after the race briefing. Swim hats are compulsory and will be provided.

You will be asked to enter the water and line up at or behind the start line. The swim will start in the water. The start will be prompt, to provide the most accurate times for you.

The temperature of the lake is taken on the morning of the event and if it is over 14c then wetsuits will be optional. If the temperature is over 22 degrees then wetsuits will not be allowed. NB: We can’t tell you if wetsuits will be allowed at the race until the temperature is taken on race day.

If you have any recent exposed cuts or feel unwell you are advised not to take part. If you get into any sort of difficulty, roll onto your back and raise one arm directly upwards out of the water. This will prompt a lifeguard in a kayak to either rescue or attend to you out in the open water.

The route is clockwise. The course will be well marked with swim buoys and you will complete 1 lap for the sprint distance and 2 laps for the standard distance. After completing your correct number of laps, you will head for the swim exit marked by flags.

Bike Course: After securing your cycle helmet in the transition area, (this must be done before un-racking your bike), proceed on foot to the mount point, where you must wait until it is clear to start the bike course.

You must ensure you mount and dismount correctly, (i.e. after the mount line and before the dismount line), failure to do so will result in a time penalty!

The 5km bike loop will be completed 4 times for the sprint distance, and 8 times for the standard distance. It is your responsibility to count your own laps. We find the best way of doing this is with the aid of a bike computer or watch.

Run Course: Starting from the transition area, triathletes will run either 1 or two out and back loops, alongside the lake. The course is on pavements and is completely flat. There will be 1 drinks station on the course, which you will pass on each lap.

After the Race No bikes can be removed from transition until the last cyclist has returned in your wave. Your number must be presented to remove your bike. There will be no exception to this!

BTF (British Triathlon Federation) rules apply. All these rules are important but the most important of these is that all competitors must secure their cycle helmet (on their heads!) before removing their bike from the rack and must not undo or remove it before racking their bike at the end of the cycle section.

You must also fully comply with and follow all rules of the Highway Code. Our primary consideration is your safety, make it yours as well!

You will receive all race information, via email, in the week leading up to the event.

Please make sure you arrive at least 45 minutes before the race start so you have plenty of time to collect your Timing Chip and Race Number


There will be toilets a short distance from the transition area.


There will be an informal baggage drop area for you to leave any belongings within the transition area.


You are free to wander around the lake so you can see where the competitors will be running. It is lapped so you will see them on numerous occasions.


Event Chip Timing will record your times. Results will be live at throughout and after the race.

Prizes Presentation

The presentation of prizes will take place throughout the morning and we’ll make announcements prior to the presentation. There are lots of prizes on offer!


We will have a photographer taking a few snaps of the race and they will be on our Facebook page after the race so be sure to check it out and see if you can spot yourself.

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Booking on has closed for this event 🙁

Please contact the race organiser direct to see if they are still accepting entries.

  • Standard Triathlon 1500m swim, 40 km bike, 10 km run
    £58 CLOSED
  • Sprint Triathlon 750m swim, 20 km bike, 5 km run
    £48 CLOSED


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